• 0.01 Hz to 12 MHz Frequency Range
• 0.0005% Synthesized Accuracy
• Pulse Capability
• GPIB (IEEE 488) Standard
• 200V Output Protection
Compact and Versatile
Model 278 Programmable Synthesized Function Generator is a
light-weight, half-rack instrument for bench or ATE use. The
278 can generate precise sine, triangle, square, pulse, and
external width controlled waveforms from 0.01 to 10 Vp-p,
and dc offsets within a - 5 to + 5V range into 50Ω.
Waveforms can be continuous, gated, or triggered.
The 278’s synthesized mode has 5 digit frequency resoution
with 0.0005% accuracy, or it can be locked to an external 10
MHz frequency standard for even greater accuracy and
stability. Other 278 features include phase locking to an
external frequency and use of the
synthesizer circuit as a highly accurate internal trigger.
Programmable Pulse Widths
The 278 can function as a pulse generator with pulse widths
programmable from 45 ns to 500 ms with 2 digits of
resolution. To make its use as a pulse generator more
versatile, the 278 can also program upper and lower levels
rather than amplitude and offset, and periods from 90 ns to
1 sec with 3 digits of resolution.
Ease of Programming
The GPIB entry sequence is identical to front panel entry
and the ASCII character for GPIB programming appears with
each key on the f ront- panel. This makes it easy to
transfer a manual setup to a controller program or vice
versa. To help the
operator even more, "command recall” can display up to 40
previous characters entered either at the front panel or by
GPIB. The 278 also features free-format numeric entry,
parameter independence until a final execute command, and
front panel GPIB address selection (which can, however, be
locked out for security).
All 278 outputs are protected against short circuits and
excessive voltages between ± 15V. The main output is further
protected against voltage inputs of up to 140 Vac or ±
200Vdc. If avoltagegreaterthan ±
15Visappliedtothemainoutput, the 278 generates a audible
alarm, a front panel error message, and a GPIB service
request. Inputs are protected from voltages up to ± 50V.